You know how sometimes you don't particularly like a song--or you even dislike it--but then you hear it in a movie or TV show that you like and it totally changes how you feel about it? That happened to me with Islands In the Stream....after seeing it on Gavin and Stacey, I now really love it! Weird that an English show set in Wales is what helped me appreciate Dolly Parton and Kenny Rogers. Well, whatever works!
In this scene, two of the Welsh characters perform this song. I can't remember if the actors are actually Welsh or English.